1. Field of the Invention
This invention relates to utility racks for pick-up truck cargo beds and particularly such utility racks for carrying ladders and other items of substantial length which may typically exceed the length of a cargo bed. The invention also relates to such utility racks as they include enhanced rails, such as unistructurally formed rails, to create platforms for mounting items to be transported, e.g. tool boxes, storage bins, adapter plate mounted machinery, generators, compressors, and the like.
2. Prior Art Statement
With the development of cargo bed trucks came racks to support items for transport--frames for carrying lumber, glass, ladders, etc. They were initially made of wood and took on a box-like open frame configuration. Subsequently, metal racks were developed to increase both strength and longevity. While the development of ladder utility racks and other racks did not stand still, most improvements pertained to "enhancing" the basic open box-like framing by adding to it rather than changing the framing configuration itself.
U.S. Pat. No. 2,134,823 describes a 1938 ladder rack which is side mounted and includes a complex clamping lever U.S. Pat. No. 3,877,624 describes a ladder rack involving a plurality of bows which transverse the top of a closed truck, wherein one of the bows has clamps to clamp ladders. The bows are independently attached to the vehicle and are not connected in any fashion. Further, they appear not to be adaptable to cargo beds for carrying items having lengths greater that the cargo bed.
U.S. Pat. No. 4,390,117 describes a ladder rack for vehicles involving parallel side members and transverse cross members. It is adapted for mounting on the roof of a vehicle and, again, would not be effective for a pick-up bed. Also, complex rack attachment and ladder attachment mechanisms are included.
U.S. Pat. No. 4,444,427 teaches an auxiliary structured element for pick-up cargo beds which includes a four sided frame and subsequent cross members for mounting a deck, e.g. a top with an access door.
U.S. Pat. No. 4,984,837 is directed to a load support assembly for pick-up trucks. This device has vertical mounting supports and a tiltable load support cross member. It is used for transporting items in the cargo bed tilted upwardly and forwardly; it is cab mounted and cannot carry lengthy items in a horizontal position.
Most recently issued U.S. Pat. No. 5,002,324 describes a utility rack for pick-up cargo beds. The rack has two inverted "U" type stanchions attached to a continuous rail that encompasses both sidewalls and the forward wall of the cargo bed, itself forming a "U" type configuration in the horizontal plane. The rear stanchion is movable and removable. This is different from the present invention in the extra weight and material required for the forward wall section of the continuous rail, whereas the present invention relies upon parallel rails not connected directly to one another. It is also more difficult to install since this prior art device has exact fixed width of separation of the rail due to the direct connection. It is also subject to loosening and wearing of the rear stanchion mounting parts and even subject to the possibility of accidental disassemblage of the rear stanchion. Finally, because of the need for close tolerances of the rear stanchion and its mounts, the precise separation of the rail at its rear portion is essential to enable a user to subsequently mount the rear stanchion. None of those shortcomings exist with the present invention device.